Walking roof support



w. A. BLOWER ETAL 2,795,936

WALKING ROOF SUPPORT June 18, 1957 '4 Sheets-Sheet 1 Filed Sept. 50, 1952 lNvem'oRs WARREN A. BLOWER RICHARD LZIEGLER QQRM ATTORNEY June 18, 1957 w. A. BLOWER ETAL' WALKING ROOF SUPPORT 4 Sheets Sheet 2 Filed Sept. 30, 1952 lnvauroas WARREN A.Bl.owaa

Run-man L.ZIEGLER BY FM ATTORNEY June 18 1957 'w. A. BLOWER ElAL 2,7 6

WALKING ROOF SUPPORT Filed Sept. 50, 1952 4 Sh eets-Sheet 4 $1 FIG. 6. 8 l [90 Z mp yuqw ATTORNEY United States Patent 6 WALKING ROOF SUPPORT Warren A. Blower, Franklin, and Richard L. Ziegler, Seneca, Pa., assignors to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application September 30, 1952, Serial No. 312,182

Claims. (Cl. 61-63) This invention relates to a walking roof support, especially to a walking roof support such as is adapted to be used in mechanized mining.

The technology of mechanized mining has in the past few years brought forth machines known as continuous miners. These machines have created certain problems in connection with roof control which have commanded the attention of mining engineers and the designers of mining machinery. One of the problems is to provide a roof support which is adequate to furnish the support necessary to prevent roof falls while at the same time permitting considerable flexibility of adaptation and mobility in order to enable the roof control to keep up with the continuous miner; in other words, it is desirable to keep the continuous miner in operation constantly or with a minimum of delay because of the large capital investment, rather than have the continuous miner shut down while conventional props and timbering are put in place to prevent roof falls.

It is accordingly an object of this invention to provide a walking roof support which has the mobility necessary to enable it to move about in a mine as readily as a continuous mining machine itself, and which has the adaptability and flexibility necessary to enable it to be used under widely varying conditions. This and other objects are accomplished in a walking roof support comprising a pair of elongated members adapted to engage a roof, a variable length prop at each end of each member, a variable length strut at each end of each pair of roof engaging members and connecting the props, and means to lock each strut member in a predetermined angular relationship with at least one of the roof engaging members.

In the drawings:

' Fig. l is a top plan view of a mine interior showing a plurality of walking roof supports made according to this invention arranged to provide a mobile tunnel for a continuous mining machine;

Fig. 2 is a view in section on line 22 of Fig. l, but on a much larger scale than the scale of Fig. 1;

Fig. 3 is a view in section substantially on line 3-3 of Fig. 2 but on a larger scale;

Fig. 4 is a view in section substantially on line 4-4 of Fig. 3;

Fig. 5 is a view in section on line 5-5 of Fig. 2, with the parts in extended position; and

Fig. 6 is an operational View showing a roof support made according to this invention and the manner of walking the roof support around a corner.

As is best seen in Fig. 1, a continuous miner is shown in outline form at 2, the machine 2 being any of a number of-machines of the general type shown in patent applications Serial No. 11,688, filed February 27, 1948; Se-' rial Nos. 102,995 and 102,996, filed July 5, 1949; Serial No. 181,977, filed August 29, 1950, now matured into Patent No. 2,781,187, and Serial No. 267,717, filed January 23, 1952, now matured into Patent No. 2,751,204, and assigned to the assignee of this invention. It will 2,795,936 Patented June 18, 1957 and are arranged to form a highly mobile tunnel from which the continuous miner 2 advances into the seam of mineral, the roof supports 4 moving forward to keep pace with the continuous miner 2 .with each advance of the entire machine.

Referring now to the invention in detail, the walking roof support in its preferred form has a pair of elongated members 6 adapted to engage a roof, a prop indicated generally at 8 at each end of each member 6, each prop 8 including means to vary its own height as will be explained in greater detail below, a strut member indicated generally at 10, the strut member having a variable length and being 'swingably connected with the two props disposed at one end of the pair of elongated members, a second andsimilar strut member 10 connected'with the two props disposed at the other end of the pair of elongated members, and means to lock at least onestrut member in a predetermined angular relationship with at least one elongated member, said lock means including a friction device 14 and a pin-and-slot mechanism 16.

More specifically, the elongated roof engaging members 6 may be any conventional structural shape, here shown as I-beams. In order to make for easier identification of the four props, they are here numbered as 8a, 8b, 8c and 8d.

Each prop includes a floor-engaging member comprising a foot 18 and a leg 20. The foot 18 is preferably formed with sloping sides similar to the forward edges of skids or sled runners to enable the props to be dragged along the floor more readily. Each leg 20 is preferably a hollow cylinder adapted to receive a boss 22 formed substantially centrally on the upper face of its cooperating foot 18. The foot 18 and leg 20 may be joined together in any suitable manner, as for example by the weld shown at 24.

At its upper end, the leg 20 carries a hydraulic jack which is adapted to vary the prop length. Each such jack has a cylinder member 26, a piston 28 reciprocable in the cylinder, and a rod member 29 secured to the piston 28. The jack just described is secured to the leg 20 by means of cooperating flanges 30, 31 and threaded members 32 holding the flanges together.

One of the jack members is connected to its associated elongated member 6; in the embodiment shown, it is the rod member 29 that is connected to the roof engaging member 6 by means of spaced ears 33 welded to a base plate 34 which in turn is secured as for example by welding to the underside of a roof engaging member 6 at one end thereof. A tongue 36 on the rod member 29 extends between'the spaced cars 33, and a suitable pin 38 passes through openings in the spaced cars 33 and tongue 36 and swingably or hingedly secures the rod member 29 to one end of a roof engaging member 6.

Means are provided to prevent rotation of the rod member 29 relative to the cylinder member 26. In the preferred embodiment shown, the rotation preventing means take the form of pin-and-slot mechanism referred to above as the mechanism 16, this mechanism comprising preferably two slots 40 provided in a depending or downward extending hollow cylindrical member 42 secured to,

leg 20, carries a collar 46 which is angularly movable ouleg 20 ofthe floor-engaging member. The lock means referred to above as'inclu'ding pin-and-slot mechanism 1'6 also includes the brake mechanism 14 referred to generally above. The brake mechanism 14 is carried by the upper end ofcolla'r 46. 'To this end, several bosses 48, here shownas four'in number, are provided at the upper end of collar 46. 'The brake-mechanism 14 comprises brake shoes 50, a cooperating surface 52 on the 1eg20, and actuating mechanism for the brake shoes. To this end, a pair of opposed brake actuating arms .54 is provided to actuate the brake shoes with the help of a small hydraulic jack '56. The arms 54 are pivotally mounted on two of the bosses-48' by means of threaded members 58 screwedintothe two bosses 48 referred to. The threaded members 58 are provided with enlarged-cylindrical portious 66 (Fig. 4.) on which the arms 54 pivot. Near their opposite ends,. the.arms 54.are slotted as shown at 62 to receivea pair of guides provided by threaded members 64carried by theremaining two bosses 48. The brake shoes 50 are pivotally carried betweenthe ends of arms 54 by-means vof suitable pins 66.

At one end of the arms 54 as seen in Fig. 3, the brake actuating jack 56 is secured by means of suitable pins 68. The struts 10 referred to above are probably best shown in Fig. 5. These struts are associated with the props 8 in such a manner as to permit movement of the struts along the props axially, this movement being of course in addition to the'angular movement of the strut relative to its associated props. More specifically, the struts are secured to or associated with the collars 46, and the collars 46 are movable vertically as seen in Fig. 2 on the legs 20. A lower stop collar 70 limits the relative axial movement in one direction, and movement in the other direction is limited by engagement of stop lugs 72 with the under faces of flanges 31. The collars 46 are shown in Fig. 2 as restingon the lower stop collars 7t Inorder best to permit smoother and unimpeded movement, both axial movement and angular movement, of each collar 46 relative to its associated prop, each collar 46 is preferably provided with a bearing bushing 73 of any suitable bearing material.

. Reference was made above to the fact that the struts 10 are associated with the various props 8. The manner of this association will now be set forth in detail. As is probably best seen in Fig. 5, each strut member includes a hydraulic jack having a cylinder 74, a piston '76 reciprocable in the cylinder, and a piston rod 78 secured to the piston and extending out through suitable packing in one end of cylinder 74. Cylinder 74 is secured to the collar 46 of one 80 and threaded members 82, while piston rod 78 threadedly engages the collar 46 of the other prop as shown at 84. In addition, a locking flange 86 is provided, flange 86 being preferably welded to the piston rod 78 and being secured to its associated collar 46 by means of threaded members 88.

The strut members 10 could theoretically be provided by the jacks alone, but such a design would be undesirable as putting too much of a bending stress on the jacks. In the preferred form of the invention, means are provided to relieve the hydraulic jacks of the struts of substantially all bending stresses. To this end, a strut member aiso includes at least one slide 90 secured to one collar 46 by means of threaded members 92; slide 99 slidably en gages the other collar by means of a slot 4 provided in the collar.

Hydraulic fluid under pressure may of course be supplied to the various jacks from any suitable source through control means of any suitable conventional type. The hydraulic system and its controls form no part of this invention and are therefore not set forth in detail here. It will suffice to point out that, in the preferred embodiment of the invention shown here, each walking roof support is provided with its own source of hydraulic fluid under prop by means of a flange pressure. Thus, one of the strut members carries an electric motor"9'6 and ahy'draiilic pump"93 connected to be driven by motor 96. Motor 96 and pump 98 are mounted on a frame which includes an arm 100 formed integral with one of the collars 46 as is best seen in Fig. 2. The outer or free end of arm 100 (the left end as seen in Fig. 2) is secured in anvsuitable manner to a stirrup 102 which is in turnsecured-to the-slide 90 by threaded members 104, here shown as four in number.

:R'eferenceiwasEmade iabove 'to the "fact that at least one slide 30 is providedtoarelievethehorizontal jack of substantially allbendin'g stresses. In the preferred'form illustrated in -the drawings two such slides are provided,

one on eachside of the hydraulic jack. Where two slides are used, both slides-serve to support'the motor 96 and pump 98.

The hydraulic pump 98 may be connected to receive fluid from any suitable reservoir. Preferably each walking roof support carriesits own reservoir, shown in Fig. 2 as a tank 106 carried by an arm 108 similar to the armltltl described above. Tank 106 may be secured to arm 108 by threaded members 1 10. Suitable conventional hose lines will be provided connecting tank 106, pump 98, and the various hydraulic jacks, as will be understood by those skilled in the art.

Operation Walking roof supports made according to this invention are preferably used to provide a mobile tunnel for a continuous mining machine, supporting the roof over the continuous miner and advancing with the miner. For advancement in a substantially straight line, the operation of the invention is substantially as follows:

Assuming that the struts -10 of the invention have their jack-s collapsed, fluid is allowed to leave the cylinders 26 of the forward-props8c and 8d, with the result that the forward roof-engaging member 6b is lowered by the weight'of the apparatus until it is out of contact with the roof. The'left (as seen in Fig. 2) roof-engaging member 6a is maintained tightly'engaged with the roof. The horizontal jacks are now extended by admitting fluid to the left ends of cylinders 74, with the result that the props 8c and 8d are moved to the right into the dotted line position shown in Fig. 2. Fluid is then admitted to the lower end of cylinders 26 (it is assumed that the vertical jacks are single-acting) of the props 8c and 8d, whereupon the roof-engaging member 6b engages the roof and is held tight against the roof.

Next, fluid is permitted to leave the cylinders 26 of props 8a and 8b, with the result that roof-engaging member 6a is lowered by its own weight out of contact with the roof. Fluid is then admit-ted to the right ends of cylinders 74 of the strut members, whereupon the props 8a and 8b are dragged along the floor to the right as seen in Fig. 2.

It will of course be understood by those skilled in the art that irregularities in the floor are provided for within limits by movement of the collars 46 axially along their respective props.

Reference will now be had to Fig. 6 for a detailed understanding of the steps whereby a roof support made according to this invention is walked around a corner while supporting the roof over a continuous miner. It will of course be understood by those skilled in the art that the roof support closest to the face always has to be back far enough so as not to interfere with operation of the miner. Where the miner is provided with a side-swinging head, as in the case of the miners disclosed above, it will of course be understood by those skilled in the art that the roof support closest to the face will have to be back far enough to permit unimpeded sideswing of the head. Where the miner is turning a corner, it may be necessary in some mines to provide temporary conventional props in some locations so as not to leave too great an area of unsupported roof. This discussion will make no attempt to point out where props in addition to the i'oof support of this invention will be used, but will leave that to the discretion of the men who operate the machines in the difierent mines.

Fig. 6 shows diagrammatically how a roof support made according to this invention can be walked around a corner. A roof support made according to this invention is shown in top plan in Fig. 6 in a posit-ion which it has reached after a series of straight-ahead movements and as it is about to begin to turn a corner.

To begin walking the roof support around a corner, the operator has the roof-engaging member 6a tightly engaged with the roof, and roof-engaging member 6b is out of engagement with the roof. The brake on prop 8a remains set with the member 6a forming a right angle with the strut a. The jack of strut 10b is extended, whereupon prop 80 moves to the dotted line position 80,. The operator then moves the member 6b into engagement with the roof, and lowers member 6a out of engagement with the roof. He then collapses the jack of strut 10b, moving prop 8b into the dotted line position 8b. At the same time, prop 8a moves into the dotted line position 8a because the brake of prop 8a is set in the right angle position of member 6a and strut 10a. Prop 8d remains in the same position.

In two successive walking steps, the roof support is then walked straight forward in the new direction until prop 8c is in the position shown at 80,, prop 8b is in the position shown at 812,, etc.

(Note that the operational view shown in Fig. 6 shows the walking roof support in its various positions but showing only the center lines of the members 6a, 6b, 10a and 10b, with the feet of the props being shown as large dottedline circles, these dotted-line circles being taken for the purposes of this discussion as the various positions of the several props.)

The operator now operates the controls so that the member 6a (shown here at 6a,) is engaged with the roof, and the member 6b (shown at 6b,) is not against the roof. The brake on prop 8a (shown at 8a,) remains set. The jack of strut 10b is extended, moving prop So from position 80 to position 80,. Member 6b moves during this operation from 6b,, to 6b,. Member 6b is then brought tight up against the roof, while member 6a is lowered out of contact with the roof. The operator then collapses the jack of strut -10b, whereupon prop 8b moves from 8b to 8b,. This movement drags the prop 8a from position 8a to position 8a,.

This last step is then repeated several times, until the roof support is in the position shown by the subscripts x. It will be noted that throughout these last steps of the turning movement, the prop 8d remains in the same position. The turning movement continues with prop 8d in this same position until the operator sees that it is necessary to advance the roof support straight ahead in its new direction for one or more steps, after which the turning movement is taken up again with prop 8d in a new fixed position. The walking thus continues until the roof support is walked clear around the corner and is ready to move ahead in a new straight line direction.

It will be seen by those skilled in the art that we have here provided a highly mobile walking roof support which is readily adaptable to the requirements of mining with continuous miners and which provides roof support close to the face. Other advantages will be apparent to those skilled in the art.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without gleparting from its spirit or the scope of the appended arms.

We claim:

1. A walking foot support comprising a pair of lateral- 1y spaced elongated members adapted to engage a roof; extensible props one at each end of each of said members; a strut member swingably connected with the two props disposed at one end of the pair of elongated members; a second strut member swingably connected with the two props disposed at the other end of the pair of elongated members; means for individually extending and retracting the pairs of props associated with each of said elongated members, means for increasing the distance between the two props disposed at said one end of said elongated members when one of said elongated members is in a retracted position, means for fixing said second strut against swinging movement relative to said one of the two props disposed at the other end of the pair of elongated members, and means for decreasing the distance between the two props disposed at said one end of said elongated members when said other elongated member is in a retracted position to effect angular movement of said other elongated member about one of the two props disposed at said other end of the pair of elongated members.

2. A walking roof support as in claim 1 in which said means for fixing said second strut against swinging movement relative to said one of the two props disposed at said other end of the pair of elongated members includes friction means associated with said second strut and said prop last mentioned.

3. A walking roof support as in claim 1 in which each prop includes a floor-engaging member and a collar to which one of said strut members is fixed angularly movable on the floor engaging member, and said means for fixing said second strut against swinging movement relative to said one of the two props disposed at the other end of the pair of elongated members includes brake mechanisms associated with the collar and the floor engaging member of said last mentioned prop.

4. A walking roof support as in claim 3 in which said floor-engaging member of each prop is cylindrical, said props each having a piston reciprocable in the cylindrical floor-engaging member, a rod member secured to said piston and connectable with one of said elongated roof engaging members, and pin-and-slot means to prevent rotation of the rod member relative to the cylinder memher.

5. In a walking roof support, a pair of laterally spaced elongated members adapted to engage a roof, a prop at each end of each member and including means to vary the height thereof, each of said props also including a floor-engaging member and a collar angularly movable on the floor-engaging member, a strut member swingably connected with the two props disposed at one end of each of the elongated members, a second strut member swingably connected with the two props disposed at the other end of each of the elongated members, each of said strut members including a hydraulic jack connected with the collars of the props of each pair of props disposed at the ends of the pair of elongated roof engaging mem bers, each strut member also including a slide secured to one collar and slidably engaging the other collar of said pairs of props, and means to lock at least one strut member in a predetermined angular relationship with at least one elongated member.

References Cited in the file of this patent UNITED STATES PATENTS 1,704,866 Morgan Mar. 12, 1929 FOREIGN PATENTS 631,747 Great Britain 1949 961,322 France 1949 658,998 Great Britain 1951 

